Volley POST string request unexpected error 500

I am using Volley library in my project and getting Unexpected response code 500 as response.

I have searched stackoverflow thoroughly and still unable to find solution that works.

Following is my code for making POST string request

        val API = "http://squadtechsolution.com/android/v1/allcompany.php"
        val requestQueue = Volley.newRequestQueue(mActivity)
        val stringRequest = StringRequest(
            Request.Method.GET,
            API,
            Response.Listener { response ->
                Log.i("dxdiag", response)
                mView.onFetchHttpDataResult(true)
                Toast.makeText(context, response, Toast.LENGTH_LONG).show()
            },
            Response.ErrorListener { error ->
                Toast.makeText(context, error.toString(), Toast.LENGTH_LONG).show()
                Log.i("dxdiag", error.printStackTrace().toString())
                mView.onFetchHttpDataResult(false)
            })
        requestQueue.add(stringRequest)

Following is the stacktrace

2019-09-03 17:15:53.237 3308-3892/com.squadtechs.markhor.foodapp 
E/Volley: [194] BasicNetwork.performRequest: Unexpected response code 
500 for 
http://squadtechsolution.com/android/v1/allcompany.php
2019-09-03 17:15:53.243 3308-3351/com.squadtechs.markhor.foodapp 
D/EGL_emulation: eglMakeCurrent: 0xa7d84180: ver 2 0 (tinfo 
0xa7d832b0)
2019-09-03 17:15:53.256 3308-3308/com.squadtechs.markhor.foodapp 
W/System.err: com.android.volley.ServerError
2019-09-03 17:15:53.257 3308-3308/com.squadtechs.markhor.foodapp 
W/System.err:     at com.android.volley.toolbox.BasicNetwork.performRequest(BasicNetwork.java:205)2019-09-03 17:15:53.257 3308-3308/com.squadtechs.markhor.foodapp W/System.err:     at com.android.volley.NetworkDispatcher.processRequest(NetworkDispatcher.java:131)2019-09-03 17:15:53.257 3308-3308/com.squadtechs.markhor.foodapp W/System.err:     at com.android.volley.NetworkDispatcher.processRequest(NetworkDispatcher.java:111)2019-09-03 17:15:53.257 3308-3308/com.squadtechs.markhor.foodapp W/System.err:     at com.android.volley.NetworkDispatcher.run(NetworkDispatcher.java:90)

Following is PHP code that I wrote on server side:

<?php
    require 'db.php';

    $sql = "SELECT * FROM `company_profile`";
    $result = $con->query($sql);

    if ($result->num_rows > 0) {
    // output data of each row
    while($row = $result->fetch_assoc()) {

        $id=$row['id']; 

        $company_name=$row['company_name'];
        $cuisine=$row['cuisine'];
        $conpany_phone=$row['conpany_phone'];
        $company_description=$row['company_description']; 
        $company_logo=$row['company_logo'];
        $company_type=$row['company_type'];
        $delivery_type=$row['delivery_type'];
        $delivery_range=$row['delivery_range']; 
        $delivery_fee=$row['delivery_fee'];
        $delivery_pickupinfo=$row['delivery_pickupinfo'];
        $address=$row['address'];

        $companyData[] = array('id'=> $id,'company_name'=> 
        $company_name,'cuisine'=> $cuisine,'conpany_phone'=> 
        $conpany_phone,'company_description'=> 
        $company_description,'company_logo'=> $company_logo,'company_type'=> 
        $company_type,'delivery_type'=> $delivery_type,'delivery_range'=> 
        $delivery_range,'delivery_fee'=> 
        $delivery_fee,'delivery_pickupinfo'=> $delivery_pickupinfo,'address'=> $address);   
    }
    echo $jsonformat=json_encode($companyData);
    } else {
        echo "0 results";
    }
    $conn->close();
?>

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